Disconnection and rippling of the ion tail of comet Hale-Bopp

Abstract

We give results of our large-scale observations near perihelion of Comet Hale-Bopp. On 1997-02-16/17/18 a disconnection event occurred in the ion tail. During our observation, matter in the tail was moving at about 50 km/s, and the ion ray was approaching the main axis of the main tail at about 0.080 arcmin/s. On 1997-03-03, rippling occurred in the ion tail, at a distance of about 130×10 4 km from the density centre, and at 30° from the main axis, with an amplitude of about 20×10 4 km, an ion beam width of about 8×10 4 km, and a phase velocity of about 200 km/s.